The Hulko-Droid is a robot that appears in Sonic the Comic Issue #88 in the Tails story, Small Change.
Hulko-Droid was a robot created by Slimy, Grimer's cousin. The droid was constructed to "crush" villagers, with the aim being for Slimy to steal Grimer's job. Unfortunately, the robot was shoddily made; Tails had been recently been shrunk by Slimy's reducing ray (and was almost crushed by the robot) but was able to find a gap in Hulko's armour. From inside, Tails was easily able to destroy the wiring and cause the robot to fall apart. Slimy then accidentally fired his reducing ray at the remains of Hulko-Droid, causing it to reflect back at him and shrink him to practically nothing.